Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"boron trifluoride"”.
-
Preparation and Properties of Azetidine-2-Ones
… In the presence of boron trifluoride etherate and toluene as solvent the rearrangement of azetidine-2-ones results in the formation of a propionamide by ring opening of the azetidinone and electrophilic substitution of the intermediate into the aromatic ring of the …
-
Nuclear Magnetic Resonance Studies of Acid-Base Interactions: Part I. Proton Magnetic Resonance Studies of Hydrogen Bonding. Part Ii. J(boron-11-Fluorine-19) in Boron Trifluoride and Its Derivatives
Made available in DSpace on 2014-12-09T17:35:02Z (GMT). No. of bitstreams: 1 6503576.pdf: 4257982 bytes, checksum: ea83a01e8f7216d223d4c2ccc7555081 (MD5) Previous issue date: 1964
-
Fading of carbonless copying paper
… from S-RB (2),f whereas the weaker Lewis acid boron trifluoride, did in fact retard the dye development. A coordination complex with a different ,tmax for 1absorptionwas detected with boron trifluoride and S-RB (2). The oxIdation of S-RB (2) on Fulacolor was shown to occur at two distinct …
-
Photonuclear reactions near threshold
… studied by observing the emitted neutrons with a boron trifluoride counter in a tank of paraffin. From considerations regarding the shapes of the cross sections curves near threshold, evidence has been obtained which indicates that electric quadupole and magnetic dipole absorption of photons …
-
Synthesis of delta-1(9)-octalinols and their analogues
… with mixtures of acetic anhydride-acetic acid-boron trifluoride proved unsuccessful. Two model compounds derived from hecogenin and incorporating the octalinol residue 1 were also prepared in the hope that the analogous ketone 2 might be obtained. This reaction, too, was unsuccessful.
-
NMR studies of mixed tetrahaloborates and some related boron trihalide complexes /|nGary John Schrobilgen. -- 260 St. Catharines, Ont. : [s. n.],
… been used to study donor-acceptor complexes of boron trifluoride with several ureas, tetramethylthiourea, tetramethylselenourea, and tetramethylquanidine as well as adducts of tetramethyl- -urea with BF2Cl, BFC1 2 , and BC1 3 - A large number of mixed tetrahaloborate ions, including some of the …
-
Stereospecific Syntheses from Podocarpic Acid
… methoxy acid (4) ( Scheme 1 ) . A study of the boron trifluoride rearrangements of the three epoxides (12), (13), and (14), has been made using benzene and dimethyl sulphoxide as solvents. The stereochemistry of a series of 6-bromo-7-oxo derivatives of diterpenoids possessing an aromatic ring-C …
-
I. Sulfonium-Mediated Oxidative Glycosylation of Glycal Donors for the Synthesis of C(2)-Hydroxy-Beta-Glycosides. II. Hypervalent Iodine (iii)-Mediated Oxidative Glycosylation of Glycal Donors for the Synthesis of C(2)-Acyloxy-Beta-Glycosides. III. Efforts Toward the Synthesis of Immunologic Adjuvant Qs-21a(api)
… were activated with bisacyliodobenzene and boron trifluoride diethyl etherate for the synthesis of 1,2-trans -C2-acyloxy-beta-glycoside with the application to assemble non-C2-branched oligosaccharides. In the third section of this thesis, an acylated triterpene glycoside QS-21Aapi was …
-
Asymmetric synthesis of novel anthracyclinones
… Stronger Lewis acids gave poorer selectivity and boron trifluoride etherate reacted slowly with (30) but with high selectivity to give the diastereomerically pure fluorotetracycle (91) in 58% yield. The presence of a β-methoxy group in the substrate leads to decreased stereoselectivity due to …
-
A Study of Lewis Acid-Base Interactions: Part 1 - a Tin-119 Moessbauer and Tin-119 Nmr Study of the 1: 1 Lewis Base Adducts of Trimethyltin Chloride. Part 2 - a Calorimetric, and F(19), B(11), and H(1) Nmr Study of the Lewis Base Adducts of Boron-Trifluoride
Made available in DSpace on 2014-12-09T17:36:13Z (GMT). No. of bitstreams: 1 6910722.pdf: 5353101 bytes, checksum: 36aca5a579ee06afcbff0064c0a9f87d (MD5) Previous issue date: 1968
-
Analysis and characterisation of an acylphosphine oxide photoinitiator
… (HQ)), acids (methyl sulphonic acid (MSA) and boron trifluoride dihydrate (BF3∙2H2O)) and water present in the solvent were also investigated. These studies were monitored over time using LC-UV and CE-UV methods. Mass spectrometry was employed for the first time to investigate the pathways and …
-
Macrocyclic chemistry: Part I - Characterization of a mixed-valence di-iron complex and synthesis of a new poly-iron complex. Part II - Synthesis, characterization of new diphosphoester macrocyclic polyethers
… reduction of iron mono-keto-macrocycles with boron trifluoride and triethylsilane showed a coupling reaction to form a di-iron complex. A mixture of iron mono-keto-macrocycic with iron diketo-dimacrocycle showed a new species with an intense NIR absorption at 1010 nm. This intense band at 1010 …
-
Dipole moments and Kerr effect of poly(n-vinylcarbazole) and its complexes with trinitrofluorenone
… and cationic catalysts (boron-trifluoride etherate and aluminium chloride). The polymers produced were characterised by molecular weight measurements and powder x-ray diffraction. The tacticity of the polymer samples was determined using proton and carbon-13 nuclear …
-
Studies in ring D fragmentation of estrone
… 10)-trien, Fragmentation with the borontrifluoride diethyl ether complex resulted in formation of the undesired 3-methoxy13,17-secoestra-l ,3,5(1 0),l4-tetraen-17-nitrile. Since the 15β-trimethylsilyl group did not direct the fragmentation, the …
-
Design and synthesis of rotational analogues of estradiol
… was obtained as the minor product of the boron trifluoride mediated reaction between the 14, 16-diene and methyl vinyl ketone (MVK). The major compound was formulated 16a.-acetyl-3-methoxy-17P-3'- oxobutyl-14, l 7a.-ethenoestra-1,3,5(10)-triene, on the basis of the available spectral data. …
-
Oxo, imido, and nitrido compounds of osmium(VI)
… The compound reacted with boron trifluoride to form an adduct in solution and with methyltrifluoromethane sulfonate to form the methylimide, (($\eta\sp5$-C$\sb5$H$\sb5$)Os(NMe)(CH$\sb2$SiMe$\sb3$)$\sb2$) (OSO$\sb2$CF$\sb3$). The crystal structure of the silver dimer was …
-
A New Synthesis of enantiopure C-3-substituted Glutamates by Utilization of Ortho Ester protected (S)-Pyroglutamic acid
… After rearrangement with boron trifluoride, the ortho ester derivatives (Acceptor=Cbz,CO2Me) were at hand and exclusively the N-Cbz derivative was converted to the corresponding alpha,beta-unsaturated lactam via a syn-elimination reaction. The formation of the …
-
A measurement of the resonance escape probability of neutrons in a homogeneous thorium reactor
… in the direction of the neutron beam with a bare boron trifluoride detector. The area under a curve of neutron density versus spatial position was obtained for various concentrations of absorber. The above process was carried out for the thorium solution and for a “mock solution," whose …
Page 1 of 2